You can create and run a command simultaneously by using the immediate execution feature.

Prerequisites

  • The instances on which you want to run a command are in the Running state.
  • You can retain a maximum of 100 Cloud Assistant commands within an Alibaba Cloud region. This quota may increase based on your ECS usage. If you use the immediate execution feature and turn off Save Command when you are creating a command, the command does not consume your command quota.
    Note Alternatively, you can call the DescribeAccountAttributes operation with AttributeName.N set to max-axt-command-count to query the maximum number of Cloud Assistant commands that you can retain within a region.
  • You can run Cloud Assistant commands up to 5,000 times within a region per day. This quota may increase with your ECS usage.
    Note You can also call the DescribeAccountAttributes operation with the AttributeName.N parameter set to max-axt-invocation-daily to query the maximum number of times that you can run Cloud Assistant commands within in a region per day.

Background information

When you use the immediate execution feature, take note of the following items:

  • A command cannot exceed 16 KB in size after it is encoded in Base64.
  • A maximum of 20 custom parameters can be specified in a Cloud Assistant command.
  • You can run a command on a maximum of 50 instances at a time by calling an API operation.
  • When you create a command, you must check whether the syntax, logic, and algorithm of the command are correct.

    For example, assume that you have created the /backup directory (mkdir /backup) on an instance, you can run the following shell commands to archive a file in this directory: 

    #! /bin/bash 
OF=/backup/my-backup-$(date +%Y%m%d).tgz
tar -cf $OF {{file}}
    Note In this example, {{file}} is a custom parameter. When you run the commands, you can set this custom parameter to the name of the file to be archived. Example: /app/usrcredential. Custom parameters can be used in scenarios of dynamic values and multi-purpose values. We recommend that you specify custom parameters for security-sensitive data or data that changes based on the environment. Such data includes AccessKey pairs, instance IDs, authorization codes, time parameters, and critical system files.

Procedure

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Maintenance & Monitoring > Cloud Assistant.
  3. In the top navigation bar, select a region.
  4. Click Create or Run Command.
  5. In the Command Information section, configure the parameters for the command.
    The following table describes the parameters.
    Parameter Description
    Command Source The source of the command.
    • New Command: creates a command.
    • Existing Command: selects an existing command.
    Command Name The name of the command.
    Command Type The type of the command.
    • For Linux instances, select Shell.
    • For Windows instances, select Bat or PowerShell.
    Command The content of the command. You can enter or paste the command content.

    For more information about shell commands, see View instance configurations.

    Use Parameters Specifies whether to use parameters.

    If you turn on Use Parameters, you can specify custom parameters in the {{key}} format in the Command field.

    Command Parameters The values of the custom parameters specified in the {{key}} format in the Command field.

    This parameter is available only when Use Parameters is turned on.

    Save Command Specifies whether to save the command.
    Command Description The description of the command. We recommend that you enter information such as the purpose of the command to facilitate subsequent management and maintenance.
    Execution Path The custom execution path of the command. The following list provides default execution paths for instances that use different operating systems:
    • For Linux instances, the default execution path is the /home directory of the root user.
    • For Windows instances, the default execution path is the directory where the process of the Cloud Assistant client is located, such as C:\ProgramData\aliyun\assist\$(version).
    Timeout Period The timeout period for the command to run on instances. If a task that runs a command times out, Cloud Assistant forcibly stops the task process.

    Unit: seconds. Default value: 60. Minimum value: 10. If you set Timeout Period to a value of less than 10 seconds, the system changes the value to 10 seconds to ensure that the execution succeeds.

  6. In the Select Instances section, select the instances on which you want to run the command.
  7. Click Create Task.

What to do next

Query execution results and fix common problems